A series of explosions rocked Syria Saturday, leaving at least five people dead as a U.N. observer mission continued efforts to monitor a frayed cease-fire between the government and the opposition brokered by international envoy Kofi Annan.

The Syrian Observatory for Human Rights said the deaths occurred in the northern city of Aleppo after a bomb struck a car wash as a bus was passing by.

Activists said two blasts shook Damascus, including one caused by a bomb planted under a military vehicle. Another explosion destroyed a number of cars.

There were no immediate claims of responsibility.

About 40 U.N. observers, currently on the ground in Syria, inspected army posts in the Douma and Harasta neighborhoods of the capital, Damascus, Saturday, while mourners clashed with security forces in the Kafr Souseh neighborhood. The protests erupted after a funeral for people killed by Syrian forces a day earlier.

The violence comes as Syria prepares for parliamentary elections Monday, under constitutional reforms that have allowed the creation of new political parties.

Meanwhile, the head of the U.N. mission in Syria, Norwegian General Robert Mood, told VOA his team has already seen "very specific, concrete steps on the ground," including a significant reduction in shooting and shelling.

Mood said he sees reason for hope because he gets a sense that all the players are eager to move forward on the basis of political solutions. He added the players see that "the alternative, more violence, more kids being killed, more trouble for families in the hot spots, is a very bad alternative."

The U.N. mission hopes to have 300 observers in Syria by the end of May.

The United Nations estimates at least 9,000 people have been killed in the crackdown on the opposition, while the government says it has lost at least 2,600 of its forces to "foreign-backed terrorists."

The violence has been ongoing since anti-government protests in Syria began more than a year ago.